George W. Bush listens as Ariel Sharon, left, reads a statement at joint news conference following their talks

Israeli Prime Minister Ariel Sharon has wrapped up his visit to the United States. His discussions with President Bush and other leaders focused on the planned withdrawal of Jewish settlers from the Gaza Strip, the expansion of settlements in the West Bank and concerns about Iran's nuclear program.

For years, U.S. and Israeli leaders have debated the thorny issue of Jewish settlements in the Palestinian territories.

Under the "road map" peace plan unveiled in 2003, there is supposed to be a freeze in settlement activity.

It calls on Israel to dismantle small outposts Jewish settlers have established in the West Bank.

Both Israel and the Palestinians agreed to the road map, but neither side has taken significant strides to begin implementing the plan.

When President Bush spoke to reporters at his Texas ranch after meeting there with Prime Minister Sharon, he made clear what his administration expects Israel to do.

"I told the prime minister of my concern that Israel not undertake any activity that contravenes road map obligations, or prejudices final status negotiations. Therefore, Israel should remove unauthorized outposts, and meet its road map obligations regarding settlements in the West Bank," said Mr. Bush.

Prime Minister Sharon did pledge to follow the road map, although he says he expects to keep many large settlements inside Israel, if and when final borders are drawn for a Palestinian state.

"Regarding the unauthorized outposts, I wish to reiterate that Israel is a society governed by the rule of law. As such, I will fulfill my commitment to you, Mr. President, to remove unauthorized outposts and settlements. Israel will meet all its obligations under the road map," Mr. Sharon said.

U.S. and Israeli officials say Mr. Sharon argued that once Tehran resolves some technical problems, there will be no way to stop Iran from building a nuclear bomb.

Iran insists its nuclear program is for peaceful applications.

The two leaders also discussed Mr. Sharon's plan to withdraw about 8,500 Jewish settlers from the Gaza Strip and a small section of the West Bank in July.

Thousands of soldiers and police are expected to be needed, since many of the settlers may have to be removed by force.

President Bush endorsed the Gaza withdrawal plan and urged the Palestinians to coordinate the move with the Israelis.

"I strongly support his courageous initiative to disengage from Gaza and part of the West Bank," he said. "The prime minister is willing to coordinate the implementation of the disengagement plan with the Palestinians. I urge the Palestinian leadership to accept his offer."

President Bush says he hopes the Gaza withdrawal will re-energize efforts to implement the road map.

David Makovsky, the director of the Project on the Middle East Peace Process at the Washington Institute for Near East Policy, says a peaceful pullout from Gaza must occur before any meaningful progress can be made on the road map.

"While it would have been nice to reactivate the road map now, the reality is, I think, that will only occur after Gaza," he said. "I think disengagement has to be done well. If it happens well, the moderates in both camps are going to want to push their leaders to go further and faster on this peace process. If it is considered a fiasco, it will be a boost for rejectionists."

Earlier this year Palestinians elected Mahmoud Abbas as president, and are scheduled to choose members of a new parliament in July.

Mr. Makovsky says both the Palestinians and Israelis need help from the United States to maintain what has recently been an uneasy calm in the region.

"You have a potential partner with Mahmoud Abbas, and I think it is critical that the United States intervene on the issue of the cease-fire, on the issue of helping to coordinate the disengagement," added Mr. Makovsky. "I fear, if we don't have coordination and a narrowing of the expectations gap, I fear we will slide back into the violence, the terror of the last four-and-a-half-years and this would be a tragedy for everybody."

President Abbas has been praised by the Bush administration for instituting reforms within the Palestinian Authority and negotiating a cease-fire with the Israelis.

Prime Minister Sharon has called on Mr. Abbas to do more by totally dismantling any terrorist infrastructure in the Palestinian territories.

Mr. Abbas is scheduled to meet with President Bush during a visit to Washington expected to take place next month.

Following his meeting with Mr. Bush at the president's Texas ranch, Mr. Sharon traveled to Washington for talks with other U.S. leaders and Jewish groups.